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Abstract

A series of primarily laboratory-based studies found attention bias modification in
socially anxious participants to lead to reduced anxiety. It is argued that the failure
to replicate the positive results of attention bias modification in the study of Carlbring
et al. may be due to reasons other than the application through the Internet. A number
of controlled studies failed to replicate the positive effects of attention bias modification
in clinically rather than subclinically socially anxious subjects. Given the lack
of robust evidence for attention bias modification in clinically socially anxious
individuals, the author is inclined to consider attention bias modification as 'the
Emperor's new suit'. Results achieved with regular Internet-based treatments for social
anxiety disorder based on cognitive therapy and exposure methods are much better than
those achieved with attention bias modification procedures delivered 'face to face'
in clinically distressed participants. Given the lack of robust evidence for attention
bias modification in clinical samples, there is no need yet to investigate the implementation
of attention bias modification through the Internet.

Keywords:

Background

A growing number of studies have accumulated over the past 30 years that support the
psychological treatment of social anxiety disorder [1,2]. In a meta-analysis of active treatments in clinically relevant samples, Powers et al. [2] found clear support for cognitive-behavioral treatments (CBTs). Contrary to what
one would expect, cognitive therapy did not outperform exposure treatment; neither
did cognitive therapy enhance the effects of exposure-based treatments. It is interesting
to note that, while not significantly different, exposure methods produced the largest
controlled effect size relative to cognitive or combined methods. Nevertheless, cognitive
therapies are very popular among clinicians, as is research into cognitive mechanisms
in social anxiety disorders. Although the emphasis was originally on explicit measures,
more recent research in the domain of experimental psychopathology has increasingly
focused on implicit processes involved in anxiety disorders, including attentional
bias. A series of primarily laboratory-based studies found attention bias modification
in socially anxious participants to lead to reduced anxiety [3]. In the randomized controlled trial (RCT) of Carlbring et al. [4], this procedure was applied through the Internet, but the positive effects of attention
bias training found in previous studies could not be replicated in clinically socially
anxious individuals. The authors of this RCT interpret the failure to replicate these
positive results primarily in terms of problems associated with the delivery of attention
training through the Internet. The aim of this paper is to discuss other potential
reasons for these negative results and the current problems with the implementation
of attention training in clinical samples.

Clinical relevance of research into experimental psychopathology

Research into experimental psychopathology has grown exponentially over the last two
decades, but -despite hundreds of studies published in journals such as Behaviour Research and Therapy, Journal of Abnormal Psychology and Journal of Behavior Therapy and Experimental Psychiatry, this type of research has resulted in hardly any clinical application. A large series
of analogue studies in non-clinical samples has consistently shown that attention
bias and anxiety are related [5]. Although this is usually interpreted as evidence for attentional bias being a vulnerability
factor for developing anxiety, only few studies investigated this directly [6]. So far, the only promising clinical applications derived from research into experimental
psychopathology are cognitive bias modification procedures. Cognitive bias modification
procedures systematically train changes in patterns of selective attention and selective
interpretation. Based on cognitive theories of social anxiety, which hold that socially
anxious individuals selectively attend to social threat cues, it is assumed that changing
these biases by attention bias modification will lead to positive changes in social
anxiety. Over the course of many trials, participants are expected to implicitly learn
to attend selectively to non-threatening stimuli rather than threatening stimuli.
These studies showed that anxious individuals are no faster to respond to probes replacing
threat cues than to non-threat cues, but they are slower to respond to probes that
are opposite to threat cues relative to non-threat cues.

Although originally evaluated in analogue samples, typically consisting of paid undergraduate
(psychology) students [3,7], a few studies have now evaluated the effects of attention bias modification in more
clinically relevant socially anxious individuals, including the study of Carlbring
et al. [4]. Although two RCTs found eight sessions of attention bias modification to be superior
to a comparable placebo condition [8,9], results on clinician rating and self-report questionnaires in the Schmidt et al. study [9] were non-significant at post-treatment; results only became statistically significant
at the four-month follow-up. Between-group effect sizes (Cohen's d) at follow-up (d
= 0.35 to 0.41) were small. Although using the identical treatment protocol to Schmidt
et al., Amir et al. [8] found much larger between-group differences (d = 0.69 to 1.59) than in the Schmidt
et al. study [9]. These differences in outcome are difficult to explain, given that the same materials
and procedures were used in the two studies. Additionally, in another recent RCT [10], there were no significant group × time interactions for the self-reported measures
of anxiety. Further, engagement toward non-threat cues did not have any effect, only
training to disengage from threat led to a small reduction in anxiety, but only on
a behavioral measure. Other negative results of attention bias modification with clinically
socially anxious individuals were reported in an RCT by Julian et al. [11]. These authors also used identical assessment and training procedures to those used
by Amir et al. [8]. An RCT by McEvoy and Perini [12] using a different attention training task revealed that attention training did not
enhance the effects of standard CBTs in clinically socially anxious individuals. Finally,
theoretically, there is still no robust evidence that the cognitive change found is
predicted by performance changes on a cognitive task measuring the cognitive process
of interest [10].

Taken together, the results of the studies investigating attention training in clinically
socially anxious individuals suggest there is no robust evidence that attention training
is of clinical value. So far, only the study by Amir et al. [8] has produced clinically relevant results, which are difficult to interpret given
the small or negative results of a series of other clinical studies [4,9-12].

Do we need attention bias modification in internet-based treatment?

Given the lack of robust evidence for attention bias modification in clinical samples,
there is no need yet to investigate the implementation of attention bias modification
using the Internet. Internet-based treatments for social phobia have been intensively
studied in the last few years [13]. Results reveal that Internet-based CBT treatments for social phobia are generally
more effective than waiting list control. Face-to-face treatment for fear of public
speaking has been shown to be as effective and accepted as the same treatment applied
over the Internet without any contact with a therapist, but contact with the therapist
during treatment increases treatment compliance and enhances treatment outcome. In
a recent study by this author's group [14], an exposure-based Internet treatment 'Talk to me' was compared with a waiting list
control group. The 'Talk to me' treatment was significantly more effective than the
control treatment on a number of measures: fear and avoidance to the target behaviors,
fear of public speaking, and work impairment. Regarding the effect size (Cohen's d)
for the measures related to social phobia the Internet treatment had a high within-group
(d = 1.13) and between-group (d = 0.86) effect size. The effect sizes achieved with
the 'Talk to me' program are comparable to results of face-to-face treatment of social
phobia in a recent meta-analysis by Powers et al. [2]. Thus, results achieved with regular Internet-based treatments for social anxiety
based on cognitive therapy and exposure methods are much better than those achieved
with attention bias modification procedures.

Future research

If attention bias modification is indeed related to improvement of social anxiety,
which has not yet been demonstrated convincingly, it would be very interesting to
see whether the same applies to evidence-based psychological treatments. One study
[15] found that successful CBT led to reduced attention bias in socially anxious individuals,
but this study was published about 20 years ago. So there is a clear need for studies
investigating the impact of successful cognitive therapy on attentional bias. The
most effective treatment for social phobia is probably exposure in vivo [2]. Whether changes in attentional bias and interpretation bias are also achieved with
pure exposure methods is theoretically very interesting. Are the patients who most
improve with exposure also the ones who most normalize their attentional bias? Also,
research is needed to establish whether patients who improve with cognitive and exposure
methods, but who do not change the attention and interpretation biases, are more at
risk for relapse than patients who improve and change these biases.

One of the factors involved in the improvements achieved with attention bias modification
may be expectancy of therapeutic gain. One way of investigating the potential role
of expectancy of therapeutic gain is by varying the instructions individuals receive.
For example, half of the participants undergoing attention bias modification and control
procedures may be informed that they will undergo a bonafide treatment for social
anxiety, while the other half might be led to believe that they are participating
in a study investigating threat cues and neutral cues on physiology. Such designs
were popular in the 1970s, but may still be valuable to rule out the role played by
demand characteristics in attention bias and interpretation training.

Conclusions

Most of the evidence in favor of cognitive modification procedures is based on analogue
research and few studies have investigated the effects in clinical samples. As noted
by Beard [6], none of the studies followed the Consolidated Standards of Reporting Trials guidelines
and most did not identify a primary outcome measure. To be able to objectively evaluate
the potential benefits of these procedures, clinical trials have to be registered
in clinical trial registers before the start of the study, as was done by Carlbring
et al. [4]. By doing so, one knows how many studies have evaluated these approaches and how
many of these studies have resulted in positive or negative outcome on the primary
outcome measure. For example, to date, only one study [16] has found positive effects of cognitive bias modification in patients with generalized
anxiety disorder, but close inspection of the results reveal that results were not
evident on the worry scale, which is generally held to be the primary outcome measure
in patients with generalized anxiety disorder.

It has been argued that there is a clear need for procedures like attention bias modification,
since a number of individuals do not improve after having received evidence-based
CBT treatment. As a clinician, this author would welcome research efforts into the
additional value of attention bias modification for the failures of behavioral and
CBTs. As long as these studies are lacking, however, this author is inclined to consider
attention bias modification as 'the Emperor's new suit'.

Competing interests

The author declares that he has no competing interests.

Author's information

Since 2006, PMGE has been appointed as Academy Professor by the Royal Academy of Arts
and Sciences. He is Co-Editor-in-Chief of Clinical Psychology and Psychotherapy and Section Editor of BMC Psychiatry.